The present invention relates to rocking chairs in which a chair seat rocks with respect to a chair base.
Rocking chairs of various types have been known for many years. One type of rocking chair which is well known has a base which sits on the floor and is stationary. A rocking mechanism is provided to allow the chair to rock with respect to the stationary chair base. In the past, this mechanism has often included cooperating rocking surfaces on the chair and chair base and a spring mechanism which holds the two sections together in such a way that they rock with respect to one another. U.S. Pat. Nos. 183,366 by Born; 201,087 by Beiersdorf; 236,754 by Flinn; 354,042 by Connolly et al; and 451,490 by Kade illustrate examples of rocking chairs of this type.
A highly successful type of rocking and reclining chair is illustrated in U.S. Pat. Nos. 2,916,084 by Bottemiller et al and 4,068,888 by Bottemiller, both of which are assigned to the same assignee as the present application. In these rocking and reclining chairs, the chair seat is supported by a coil spring secured to the chair base so as to permit rocking of the chair with respect to the stationary chair base.
Recently, it has been proposed to use one or more strips of a flexible plastic material, such as a moldable epoxy glass laminate to support the chair seat with respect to the chair base. Typical arrangements of this type are shown in the Pentzien U.S. Pat. Nos. 4,119,343 and the Ward 4,141,530. In these prior structures, however, the flexible sheet or sheets are disposed either vertically or at a very substantial angle with respect to the vertical. With such a disposition of a strip however, the rocking action is not as satisfactory as might be desired. Where the strip is disposed vertically, there is a region of instability immediately about the vertical position of the strip. Where the strip is disposed at a substantial angle with respect to the vertical, the strip tends to be bent excessively and the rocking action is relatively "soft". Furthermore, with a device of this type, it is very essential to employ an adequate stop means to limit the flexing of the strip.